Device for water-cooled oil coolers

ABSTRACT

714,302. Cooling insulating-liquids for electrical apparatus. PHILIPS ELECTRICAL INDUSTRIES, Ltd. May 15, 1952 [May 18, 1951], No. 12300/52. Class 64(3) In high-voltage electrical apparatus in which liquid insulation 2 of the apparatus is cooled by a cooling liquid supplied through a pipe 4 extending through the top wall 1 of a casing enclosing the insulation, and flowing through an indirectcontact heat-exchanger immersed in the insulation, condensation of water from the air above the insulation 2 upon the pipe 4 is prevented by surrounding the pipe 4 by a hollow body 5. This body is united at the top to the wall 1, extends below the surface of the liquid insulation, and is closed at the bottom except for a passage for the pipe 4.

Jan. 22, 1957 c, EL 2,778,608

DEVICE FOR WATER-COOLED OIL COOLERS Filed May 10, 1952 2 Sheelts-Sheet 1 'INVENTOR Curt Flegel AGENT Jan. 22, 1957 c. FLEGEL 2,778;608

DEVICE FOR WATER-COOLED OIL COOLERS Filed May lO, 1952 2 Sheets-Sheet 2 INVENTOR cu RT FLEGEL BY b U611- AGENT United States Patent DEVICE FOR WATER-COOLED OIL COOLERS Curt Flegel, Hamburg-Gr.-Borstel, Germany, assignor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee Application May 10, 1952, Serial No. 287,196 Claims priority, application Germany May 18, 1951 2 Claims. (Cl. 257-198) With electrical apparatus arranged within an earthed envelope use is frequently made of oil as a high voltage insulation. Thus for example, X-ray tubes are protected in this manner from engagement with parts at a high voltage.

If heat produced in the apparatus is liable to find its way into the insulation, the latter is required to be cooled. For this purpose, the liquid may be caused to circulate and to pass a device in which the temperature is lowered. The stored heat is discharged. Rapid and efiicient heat discharge is provided by the use of a cooling liquid which flows through a pipe conduit arranged in the device, water being the liquid which is most suitable for this purpose.

Such devices are known as liquid coolers and have the disadvantage that if that part of the cooling pipe which serves for the supply of the cooling liquid is in contact with air above the level of the insulation provided in the cooler, it is coated with a film of water of condensation. The water flows into the insulation and adversely afiects its insulating properties. It lowers the breakdown voltage so that eventually sparking will take place be tween parts of the apparatus at a high voltage and the protective sheath.

This disadvantage is not experienced if the cooling pipe extends below the liquid level through the wall of the cooler. The invention permits the cooling pipe to be led through the liquid level into the cooler, the said disadvantage being avoided in that according to the invention the cooling pipe is surrounded by a hollow body which extends as far as below the surface of the liquid to be cooled and, but for a passage for the cooling pipe, is closed at the bottom end and is united at the upper end with the wall of the cooler.

In the accompanying drawing, one embodiment of the invention is shown, by way of example, to illustrate the manner in which a cooling pipe may be led through an oil cooler according to the invention.

Fig. l is a partial sectional and a partial elevational 7 view of the device according to my invention;

Fig. 2 is a perspective view of the present device as used with X-ray apparatus. Fig. 1 of the drawing shows only that part of the wall 1 of the cooler through which the cooling pipe 4 extends as far as in the oil volume 2. The wall 1 has formed in it an aperture the section of which greater than that of the pipe 4, for instance a multiple there of the wall 1 and the liquid level being separated by air'3. The wall 1 has secured to it a hollow body 5, for example a cylindrical sleeve. The latter surrounds pipe 4 and extends as far as below the oil level. The lower end of the sleeve 5 is closed by a bottom 6,

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which has an aperture formed in it for the passage of the pipe 4. The brim of the aperture is united with the pipe so that oil is prevented from passing to the outside. Instead of having a sleeve secured to it, the wall may be provided with a re-entrant part.

The temperature of the wall of the sleeve 5 and that of the oil volume of the cooler is substantially identical so that no precipitate of water of condensation is formed on the outer surface of the tube 5, the insulated properties of the oil being thus prevented from being aifeeted thereby.

Referring to Fig. 2 which shows a column 7 resting on the base portion 8 for supporting carriage 9 which is movable up and down along the column. The carriage 9 carries the supporting arm 10 which is longitudinally movable and has the container 11 enclosing an X-ray tube connected to the end thereof. High voltage supply cables 12 and 13 connect the X-ray tube to the energy supply device 14 which contains the high voltage transformer and a supply for the filament current.

One end of the housing of the X-ray tube has an inlet and an outlet portion for the circulation of the liquid insulation which passes from the container 17 through the tubes 15 and 16 to the X-ray tube. The circulation of the liquid is effected by means of a rotary pump 23 driven by an electromotor 18 on top of the container 17. A cooling pipe 19 is connected to the watertap 20 and inserted in the containerthrough the re-entrant portion or hollow receptacle as described previously. The water leaves the container 17 through the outlet pipe 21. It is clear that the water passes through the container separate from the liquid insulation.

What I claim is:

1. A cooling device for lowering the temperature of liquid insulation for high voltage electrical apparatus comprising a container having one surface provided with a reentrant portion, a cooling pipe having liquid flowing therethrough,said re-entrant portion having an aperture in a wall parallel to said surface for the passage therethrough of said cooling pipe, said liquid insulation surrounding part of said re-entrant portion, and part of said pipe extending below the liquid level being spaced from said liquid by said re-entrant portion, and another part of said pipe extending through said liquid insulation.

2. A cooling device for lowering the temperature of liquid insulation for high voltage electrical apparatus comprising a container having one surface provided with a cylindrical re-entrant portion, a cooling pipe having liquid flowing therethrough, said re-entrant portion having an aperture in a wall parallel to said surface for the passage therethrough of said cooling pipe, said wall being closed except for said aperture, said liquid insulation sur rounding part of said re-entrant portion, and part of said pipe extending below the liquid level being spaced from said liquid by said re-entrant portion and another part of said pipe extending through said liquid insulation.

References Cited in the file of this patent UNITED STATES PATENTS 1,667,621 Burnham Apr. 24, 1928 2,188,574 I Love Ian. 30, 1940 2,223,725 Heitchue Dec. 3, 1940 2,400,570 Norway May 21, 1946 

